Cigarettes as a source of heavy metal toxicity: evaluating human health risks

Abstract The present investigation assessed the levels of cadmium (Cd), chromium (Cr), lead (Pb), and nickel (Ni) in five popular brands of cigarettes that are commonly consumed in India. Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) was used to evaluate the samples. The concentrations of Cd, Cr, Pb, Ni, and As in the filler tobacco of cigarettes were 0.078 ± 0.024, 0.152 ± 0.017, 0.2512 ± 0.161, 0.178 ± 0.011, and 0.003 ± 0 μg/g, respectively, obtained from 0.5 g of tobacco from sample cigarettes C1, C2, C3, C4, and C5. This study’s results indicated that heavy metal concentrations followed the trend Pb > Ni > Cr > Cd > As. Cd showed a strong positive correlation with Pb (r = 0.965), while it also exhibited a strong negative correlation with Cr (r = − 0.287). The overall outcomes of the non-carcinogenic risk assessment (Hazard Quotient, HQ) for children and adults revealed that Cd, followed by Pb, posed a higher risk via the ingestion pathway compared to both pathways combined. Specifically, Cd and Pb posed non-carcinogenic risks for children and adults through ingestion, with HQ values exceeding 1.0 (Hazard Index > 1). In the overall results of the cancerous risk assessment of children and adults, when comparing both pathways, these heavy metals can cause highly carcinogenic risks from tobacco cigarettes through the inhalation pathway rather than the ingestion pathway. The results indicated that the tobacco contained heavy metals, presenting a significant potential health risk to users.